Undesirable vibration energy occurs in a variety of products and devices. For example, in automotive vehicles, the engine and other automotive systems can cause vibration to permeate through the vehicle body and into the vehicle's passenger compartment. Similar undesirable vibration energy occurs in a variety of other situations, such as in household appliances and other types of transportation vehicles, to name a few.
To reduce undesirable vibration energy, vibration damping materials, such as polymer resin materials, may be applied to the surfaces of mechanical components subjected to vibrational disturbances. Such damping materials dissipate a portion of the vibrational energy applied to them. For vehicle applications, such damping materials may be applied to a number of surfaces of the vehicle panels, floors, etc. to reduce the vibration or noise felt by the vehicle occupant.
In the past, many damping resins were commercially supplied in an organic solvent in order to adjust their viscosities, thereby allowing the resins to be coated or otherwise applied to a substrate. To reduce the cost and potential hazard of disposing of organic solvents, water-based polymer resins have increasingly replaced solvent-based materials. However, water-based resins suffer from certain drawbacks. In certain applications, vibration damping materials (such as those used in automobiles) may be subjected to heating during forming or finishing processes (e.g., when vehicle surfaces are painted and baked). When exposed to such heating operations, the water phase may quickly evaporate, causing the resin to crack and/or bubble, thereby compromising its structural integrity and impairing its damping performance.
Thus, a need has arisen for a damping composition that addresses the foregoing.